The secret to beautiful hair? It's in your kitchen!

Having more bad hair days than good? Take a look at your plate. Genetics aside, what you eat every day can contribute to a lustrous head of hair. Doctors have long known that some problems with your hair stem from problems with your diet. “Deficiencies of B vitamins can lead to brittle, listless hair,” says Neil Sadick, M.D., clinical professor of dermatology at the Weill Cornell Medical College in New York. “Vitamin C deficiency can lead to hair breakage. Lack of protein and essential fatty acids in the diet can lead to dry, lusterless hair.”

The key is variety: No one food is going to turn dull, lifeless hair into thick, bouncy, shiny Jessica Chastain locks. You need to put them all together. “The nutrients in different foods all work together synergistically,” says Joy Dubost, Ph.D., R.D., a spokesperson for the Academy of Nutrition and Dietetics. “By consuming lots of different foods, you allow all of the nutrients they contain to come together to do their job, and if your diet is lacking one nutrient that’s where you start to see the impact."

So, in addition to ditching harsh styling products or backing off the things that fry you hair (over processing, high heat) add a well-rounded diet to the mix to maintain healthy locks.

Oysters Said to have aphrodisiac properties, oysters are among the best dietary sources of zinc, a mineral that is often recommended to people experiencing hair loss. Some studies indicate you need zinc for normal hair pigmentation as well. “Zinc promotes cell reproduction and tissue growth and repair, all of which are important to hair health,” says Dubost. A single oyster provides about 37 milligrams (mg) of zinc, more than a day’s worth for adults. Other good sources of zinc: Red meat, whole grains, other shellfish.

Beer Hidden in all of that foam is a healthy dose of silicon, a natural element that some research suggests can help to thicken and strengthen hair. Studies have also found that silicon can improve hair that is dry and brittle. But when it comes to alcohol, more is definitely not better—the Dietary Guidelines for Americans recommend that men limit themselves to no more than two drinks a day (or two 12-ounce beers), and women should stick to one. Other (non-alcoholic) sources of silicon: Bananas, root vegetables, whole grains.

Strawberries Vitamin C is needed to maintain the natural oils on the scalp and hair to keep hair shiny, and strawberries are a good way to get it. “Vitamin C is essential to normal circulation, and good blood flow to the scalp helps keep the skin and hair healthy,” says Dubost. Adults need about 60 to 100 mg of Vitamin C per day—one cup of whole fresh strawberries provides about 85 mg. Other great sources of Vitamin C: Broccoli, sweet red and green peppers, tomato juice, citrus fruits.

Avocados A favorite ingredient in many commercial and homemade hair conditioners, avocados are rich in several nutrients including biotin, a B vitamin that promotes hair growth and scalp health. “B vitamins are coenzymes essential to helping reactions occur in the body that can promote healthy cell growth, which is important for hair,” says Dubost. “B vitamins and other coenzymes also stimulate blood flow throughout the body, including to the scalp.” Other good sources of biotin: Egg yolks, nuts, whole grains, cauliflower, bananas.

Canola Oil This common cooking oil is a great source of Vitamin E, a natural antioxidant that can help keep hair strong and flexible by protecting it from the damages of sunlight and other environmental threats that break down the protein bonds of hair and weaken it. “Many vegetable oils are rich in Vitamin E, but canola oil is versatile and easy to use in recipes, and is less expensive and has a longer shelf life than other oils,” says Dubost. One tablespoon of canola oil provides about 2.5 mg of Vitamin E, or about one-fifth of the 12 mg of Vitamin E recommend daily for adults. Other great sources of Vitamin E: Wheat germ, sunflower seeds, pine nuts, roasted almonds, safflower and sunflower oil.

Mushrooms A tasty source of antioxidants, mushrooms are also rich in pantothenic acid, also known as Vitamin B5, a coenzyme. Like other B vitamins, pantothenic acid is a favorite ingredient in shampoos and is essential to help promote healthy blood flow and normal metabolism that are needed by the scalp and hair follicles, as well as by the rest of the body. Claims that pantothenic acid can reverse hair graying or prevent hair loss are common, although more research is needed to prove that to be true. A half a cup of mushrooms offers about 10 percent of the adequate intake of pantothenic acid for adults in a day. Other great sources of pantothenic acid: Whole grains, lobster, eggs, corn.

Canned tuna Fatty fish such as canned tuna is a great source of omega-3 fatty acids. “[They] help regulate the natural oils in your scalp, which can keep your hair looking shiny,” says Dubost. “Most people don’t consume enough omega-3s. The dietary guidelines recommend that adults eat four ounces of fatty fish twice a week to provide those essential fatty acids.” Other great sources of omega-3s: Salmon, sardines, trout.

QuinoaThis grain is one of only a few plant-derived foods that provide a complete protein, complete with all of the essential amino acids in one food. (Soy is another). Hair is made up of a protein called keratin, and protein in your diet is important to the normal growth and turnover of hair cells. Too little protein in your diet can lead to dry, dull hair. A recent study in China found that animals fed a low-protein diet had thinner, shorter and fewer hairs in their coats than animals fed a higher-protein diet. In another study, German researchers found differences in the protein composition of the hair in people who were vegetarians and those who consumed meat. Women need about 46 grams of protein per day, while men need about 56 grams. One cup of cooked quinoa has about eight grams of protein (and a good amount of iron, too). Other great sources of protein: Low-fat milk and other dairy products, eggs, red meat, fish, poultry.

Spinach It's a powerhouse of Vitamin A, which is super important in the development and maintenance of epithelial cells—the layered cells that protect your body from the outside world. One half a cup of cooked spinach has more than the daily recommendation of Vitamin A for adults. Other great sources of Vitamin A: Sweet potatoes, carrots, cantaloupe.

Beans Whether you love kidney beans, black beans or pinto beans—or like them all in a big bowl of chili—beans are terrific sources of iron, a mineral that’s key to healthy hair. “Nutritional deficiencies of iron can lead to chronic hair shedding,” says Dr. Sadick. Several studies have found a link between iron deficiency and hair loss in both men and women, and many doctors now do blood tests to check iron levels in people who complain to their doctors of hair loss. A well-rounded diet that provides enough iron can help keep your hair thick and healthy. Other great sources of iron: Red meat, poultry, tofu.